C-type lectin-like domain (CTLD) of the type found in human dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) and the related receptor, DC-SIGN receptor (DC-SIGNR); CLECT_DC-SIGN_like: C-type lectin-like domain (CTLD) of the type found in human dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) and the related receptor, DC-SIGN receptor (DC-SIGNR). This group also contains proteins similar to hepatic asialoglycoprotein receptor (ASGP-R) and langerin in human. These proteins are type II membrane proteins with a CTLD ectodomain. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. DC-SIGN is thought to mediate the initial contact between dendritic cells and resting T cells, and may also mediate the rolling of DCs on epithelium. DC-SIGN and DC-SIGNR bind to oligosaccharides present on human tissues, as well as, on pathogens including parasites, bacteria, and viruses. DC-SIGN and DC-SIGNR bind to HIV enhancing viral infection of T cells. DC-SIGN and DC-SIGNR are homotetrameric, and contain four CTLDs stabilized by a coiled coil of alpha helices. The hepatic ASGP-R is an endocytic recycling receptor which binds and internalizes desialylated glycoproteins having a terminal galactose or N-acetylgalactosamine residues on their N-linked carbohydrate chains, via the clathrin-coated pit mediated endocytic pathway, and delivers them to lysosomes for degradation. It has been proposed that glycoproteins bearing terminal Sia (sialic acid) alpha2, 6GalNAc and Sia alpha2, 6Gal are endogenous ligands for ASGP-R and that ASGP-R participates in regulating the relative concentration of serum glycoproteins bearing alpha 2,6-linked Sia. The human ASGP-R is a hetero-oligomer composed of two subunits, both of which are found within this group. Langerin is expressed in a subset of dendritic leukocytes, the Langerhans cells (LC). Langerin induces the formation of Birbeck Granules (BGs) and associates with these BGs following internalization. Langerin binds, in a calcium-dependent manner, to glyco-conjugates containing mannose and related sugars mediating their uptake and degradation. Langerin molecules oligomerize as trimers with three CTLDs held together by a coiled-coil of alpha helices.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148536836  67 CPKNWKSFSSNCYFISTESASWQDSEKDCARMEAHLLVINTQEEQDFIFQNLQEESAYFVGLSDPEGQRHWQWVDQTPYN 146
Cdd:cd03590    1 CPTNWKSFQSSCYFFSTEKKSWEESRQFCEDMGAHLVIINSQEEQEFISKILSGNRSYWIGLSDEETEGEWKWVDGTPLN 80

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|
gi 148536836 147 ESSTFWHPREPSD---PNERCVVLNFRKspkrWGWNDVNCLGPQRSVCEM 193
Cdd:cd03590   81 SSKTFWHPGEPNNwggGGEDCAELVYDS----GGWNDVPCNLEYRWICEK 126

C-type lectin-like domain (CTLD) of the type found in human dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) and the related receptor, DC-SIGN receptor (DC-SIGNR); CLECT_DC-SIGN_like: C-type lectin-like domain (CTLD) of the type found in human dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) and the related receptor, DC-SIGN receptor (DC-SIGNR). This group also contains proteins similar to hepatic asialoglycoprotein receptor (ASGP-R) and langerin in human. These proteins are type II membrane proteins with a CTLD ectodomain. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. DC-SIGN is thought to mediate the initial contact between dendritic cells and resting T cells, and may also mediate the rolling of DCs on epithelium. DC-SIGN and DC-SIGNR bind to oligosaccharides present on human tissues, as well as, on pathogens including parasites, bacteria, and viruses. DC-SIGN and DC-SIGNR bind to HIV enhancing viral infection of T cells. DC-SIGN and DC-SIGNR are homotetrameric, and contain four CTLDs stabilized by a coiled coil of alpha helices. The hepatic ASGP-R is an endocytic recycling receptor which binds and internalizes desialylated glycoproteins having a terminal galactose or N-acetylgalactosamine residues on their N-linked carbohydrate chains, via the clathrin-coated pit mediated endocytic pathway, and delivers them to lysosomes for degradation. It has been proposed that glycoproteins bearing terminal Sia (sialic acid) alpha2, 6GalNAc and Sia alpha2, 6Gal are endogenous ligands for ASGP-R and that ASGP-R participates in regulating the relative concentration of serum glycoproteins bearing alpha 2,6-linked Sia. The human ASGP-R is a hetero-oligomer composed of two subunits, both of which are found within this group. Langerin is expressed in a subset of dendritic leukocytes, the Langerhans cells (LC). Langerin induces the formation of Birbeck Granules (BGs) and associates with these BGs following internalization. Langerin binds, in a calcium-dependent manner, to glyco-conjugates containing mannose and related sugars mediating their uptake and degradation. Langerin molecules oligomerize as trimers with three CTLDs held together by a coiled-coil of alpha helices.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148536836  67 CPKNWKSFSSNCYFISTESASWQDSEKDCARMEAHLLVINTQEEQDFIFQNLQEESAYFVGLSDPEGQRHWQWVDQTPYN 146
Cdd:cd03590    1 CPTNWKSFQSSCYFFSTEKKSWEESRQFCEDMGAHLVIINSQEEQEFISKILSGNRSYWIGLSDEETEGEWKWVDGTPLN 80

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|
gi 148536836 147 ESSTFWHPREPSD---PNERCVVLNFRKspkrWGWNDVNCLGPQRSVCEM 193
Cdd:cd03590   81 SSKTFWHPGEPNNwggGGEDCAELVYDS----GGWNDVPCNLEYRWICEK 126

Lectin C-type domain; This family includes both long and short form C-type

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148536836   85 SASWQDSEKDCARMEAHLLVINTQEEQDFIFQNLQEESAYF-VGLSDPEGQRHWQWVDQTPYNesSTFWHPREPSD-PNE 162
Cdd:pfam00059   1 SKTWDEAREACRKLGGHLVSINSAEELDFLSSTLKKSNKYFwIGLTDRKNEGTWKWVDGSPVN--YTNWAPEPNNNgENE 78

                          90       100       110
                  ....*....|....*....|....*....|.
gi 148536836  163 RCVVLnfrkSPKRWGWNDVNCLGPQRSVCEM 193
Cdd:pfam00059  79 DCVEL----SSSSGKWNDENCNSKNPFVCEK 105

polycystin cation channel protein; The Polycystin Cation Channel (PCC) Family (TC 1.A.5) Polycystin is a huge protein of 4303aas. Its repeated leucine-rich (LRR) segment is found in many proteins. It contains 16 polycystic kidney disease (PKD) domains, one LDL-receptor class A domain, one C-type lectin family domain, and 16-18 putative TMSs in positions between residues 2200 and 4100. Polycystin-L has been shown to be a cation (Na+, K+ and Ca2+) channel that is activated by Ca2+. Two members of the PCC family (polycystin 1 and 2) are mutated in autosomal dominant polycystic kidney disease, and polycystin-L is deleted in mice with renal and retinal defects. Note: this model is restricted to the amino half.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148536836    67 CPKNWKSF--SSNCYFISTESASWQDSEKDC-ARMEAHLLVINTQEEQDFIFQNLQE--ESAYFVGLSDPEG--QRHWQW 139
Cdd:TIGR00864  318 CPKDGEIFeeNGHCFQIVPEEAAWLDAQEQClARAGAALAIVDNDALQNFLARKVTHslDRGVWIGFSDVNGaeKGPAHQ 397

                           90       100       110       120       130
                   ....*....|....*....|....*....|....*....|....*....|....*
gi 148536836   140 VDQTPYnESSTFWHPREPSDPN-ERCVVLNfrksPKRWGWNDVnCLGPQRSVCEM 193
Cdd:TIGR00864  398 GEAFEA-EECEEGLAGEPHPARaEHCVRLD----PRGQCNSDL-CNAPHAYVCEL 446

C-type lectin-like domain (CTLD) of the type found in human dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) and the related receptor, DC-SIGN receptor (DC-SIGNR); CLECT_DC-SIGN_like: C-type lectin-like domain (CTLD) of the type found in human dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) and the related receptor, DC-SIGN receptor (DC-SIGNR). This group also contains proteins similar to hepatic asialoglycoprotein receptor (ASGP-R) and langerin in human. These proteins are type II membrane proteins with a CTLD ectodomain. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. DC-SIGN is thought to mediate the initial contact between dendritic cells and resting T cells, and may also mediate the rolling of DCs on epithelium. DC-SIGN and DC-SIGNR bind to oligosaccharides present on human tissues, as well as, on pathogens including parasites, bacteria, and viruses. DC-SIGN and DC-SIGNR bind to HIV enhancing viral infection of T cells. DC-SIGN and DC-SIGNR are homotetrameric, and contain four CTLDs stabilized by a coiled coil of alpha helices. The hepatic ASGP-R is an endocytic recycling receptor which binds and internalizes desialylated glycoproteins having a terminal galactose or N-acetylgalactosamine residues on their N-linked carbohydrate chains, via the clathrin-coated pit mediated endocytic pathway, and delivers them to lysosomes for degradation. It has been proposed that glycoproteins bearing terminal Sia (sialic acid) alpha2, 6GalNAc and Sia alpha2, 6Gal are endogenous ligands for ASGP-R and that ASGP-R participates in regulating the relative concentration of serum glycoproteins bearing alpha 2,6-linked Sia. The human ASGP-R is a hetero-oligomer composed of two subunits, both of which are found within this group. Langerin is expressed in a subset of dendritic leukocytes, the Langerhans cells (LC). Langerin induces the formation of Birbeck Granules (BGs) and associates with these BGs following internalization. Langerin binds, in a calcium-dependent manner, to glyco-conjugates containing mannose and related sugars mediating their uptake and degradation. Langerin molecules oligomerize as trimers with three CTLDs held together by a coiled-coil of alpha helices.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148536836  67 CPKNWKSFSSNCYFISTESASWQDSEKDCARMEAHLLVINTQEEQDFIFQNLQEESAYFVGLSDPEGQRHWQWVDQTPYN 146
Cdd:cd03590    1 CPTNWKSFQSSCYFFSTEKKSWEESRQFCEDMGAHLVIINSQEEQEFISKILSGNRSYWIGLSDEETEGEWKWVDGTPLN 80

                         90       100       110       120       130
                 ....*....|....*....|....*....|....*....|....*....|
gi 148536836 147 ESSTFWHPREPSD---PNERCVVLNFRKspkrWGWNDVNCLGPQRSVCEM 193
Cdd:cd03590   81 SSKTFWHPGEPNNwggGGEDCAELVYDS----GGWNDVPCNLEYRWICEK 126

C-type lectin (CTL)/C-type lectin-like (CTLD) domain; CLECT: C-type lectin (CTL)/C-type lectin-like (CTLD) domain; protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. This group is chiefly comprised of eukaryotic CTLDs, but contains some, as yet functionally uncharacterized, bacterial CTLDs. Many CTLDs are calcium-dependent carbohydrate binding modules; other CTLDs bind protein ligands, lipids, and inorganic surfaces, including CaCO3 and ice. Animal C-type lectins are involved in such functions as extracellular matrix organization, endocytosis, complement activation, pathogen recognition, and cell-cell interactions. For example: mannose-binding lectin and lung surfactant proteins A and D bind carbohydrates on surfaces (e.g. pathogens, allergens, necrotic, and apoptotic cells) and mediate functions associated with killing and phagocytosis; P (platlet)-, E (endothelial)-, and L (leukocyte)- selectins (sels) mediate the initial attachment, tethering, and rolling of lymphocytes on inflamed vascular walls enabling subsequent lymphocyte adhesion and transmigration. CTLDs may bind a variety of carbohydrate ligands including mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine, and fucose. Several CTLDs bind to protein ligands, and only some of these binding interactions are Ca2+-dependent; including the CTLDs of Coagulation Factors IX/X (IX/X) and Von Willebrand Factor (VWF) binding proteins, and natural killer cell receptors. C-type lectins, such as lithostathine, and some type II antifreeze glycoproteins function in a Ca2+-independent manner to bind inorganic surfaces. Many proteins in this group contain a single CTLD; these CTLDs associate with each other through several different surfaces to form dimers, trimers, or tetramers, from which ligand-binding sites project in different orientations. Various vertebrate type 1 transmembrane proteins including macrophage mannose receptor, endo180, phospholipase A2 receptor, and dendritic and epithelial cell receptor (DEC205) have extracellular domains containing 8 or more CTLDs; these CTLDs remain in the parent model. In some members (IX/X and VWF binding proteins), a loop extends to the adjoining domain to form a loop-swapped dimer. A similar conformation is seen in the macrophage mannose receptor CRD4's putative non-sugar bound form of the domain in the acid environment of the endosome. Lineage specific expansions of CTLDs have occurred in several animal lineages including Drosophila melanogaster and Caenorhabditis elegans; these CTLDs also remain in the parent model.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148536836  77 NCYFISTESASWQDSEKDCARMEAHLLVINTQEEQDFIFQNL--QEESAYFVGLSDPEGQRHWQWVDQTPYNeSSTFWHP 154
Cdd:cd00037    1 SCYKFSTEKLTWEEAQEYCRSLGGHLASIHSEEENDFLASLLkkSSSSDVWIGLNDLSSEGTWKWSDGSPLV-DYTNWAP 79

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|
gi 148536836 155 REP-SDPNERCVVLNFRKSpkrWGWNDVNCLGPQRSVCEM 193
Cdd:cd00037   80 GEPnPGGSEDCVVLSSSSD---GKWNDVSCSSKLPFICEK 116

Lectin C-type domain; This family includes both long and short form C-type

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148536836   85 SASWQDSEKDCARMEAHLLVINTQEEQDFIFQNLQEESAYF-VGLSDPEGQRHWQWVDQTPYNesSTFWHPREPSD-PNE 162
Cdd:pfam00059   1 SKTWDEAREACRKLGGHLVSINSAEELDFLSSTLKKSNKYFwIGLTDRKNEGTWKWVDGSPVN--YTNWAPEPNNNgENE 78

                          90       100       110
                  ....*....|....*....|....*....|.
gi 148536836  163 RCVVLnfrkSPKRWGWNDVNCLGPQRSVCEM 193
Cdd:pfam00059  79 DCVEL----SSSSGKWNDENCNSKNPFVCEK 105

C-type lectin-like domain (CTLD) of the type found in CEL-1 from Cucumaria echinata and Echinoidin from Anthocidaris crassispina; CLECT_CEL-1_like: C-type lectin-like domain (CTLD) of the type found in CEL-1 from Cucumaria echinata and Echinoidin from Anthocidaris crassispina. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. The CEL-1 CTLD binds three calcium ions and has a high specificity for N-acteylgalactosamine (GalNAc). CEL-1 exhibits strong cytotoxicity which is inhibited by GalNAc. This protein may play a role as a toxin defending against predation. Echinoidin is found in the coelomic fluid of the sea urchin and is specific for GalBeta1-3GalNAc. Echinoidin has a cell adhesive activity towards human cancer cells which is not mediated through the CTLD. Both CEL-1 and Echinoidin are multimeric proteins comprised of multiple dimers linked by disulfide bonds.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148536836  67 CPKNWKSFSSNCYFISTESASWQDSEKDC-----ARMEAHLLVINTQEEQDFIFqNLQEESA-------YFVGLSDPEGQ 134
Cdd:cd03589    1 CPTFWTAFGGYCYRFFGDRLTWEEAELRCrsfsiPGLIAHLVSIHSQEENDFVY-DLFESSRgpdtpygLWIGLHDRTSE 79

                         90       100       110       120       130       140
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 148536836 135 RHWQWVDQTPYNesSTFWHPREPSD--PNERCVVLNFRKSPKRwGWNDVNCLGPQRSVCEM 193
Cdd:cd03589   80 GPFEWTDGSPVD--FTKWAGGQPDNygGNEDCVQMWRRGDAGQ-SWNDMPCDAVFPYICKM 137

C-type lectin-like domain (CTLD) of the type found in chondroitin sulfate proteoglycan core proteins; CLECT_CSPGs: C-type lectin-like domain (CTLD) of the type found in chondroitin sulfate proteoglycan core proteins (CSPGs) in human and chicken aggrecan, frog brevican, and zebra fish dermacan. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. In cartilage, aggrecan forms cartilage link protein stabilized aggregates with hyaluronan (HA). These aggregates contribute to the tissue's load bearing properties. Aggregates having other CSPGs substituting for aggrecan may contribute to the structural integrity of many different tissues. Xenopus brevican is expressed in the notochord and the brain during early embryogenesis. Zebra fish dermacan is expressed in dermal bones and may play a role in dermal bone development. CSPGs do contain LINK domain(s) which bind HA. These LINK domains are considered by one classification system to be a variety of CTLD, but are omitted from this hierarchical classification based on insignificant sequence similarity.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148536836  67 CPKNWKSFSSNCYFISTESASWQDSEKDCARMEAHLLVINTQEEQDFIFQNLQEESayFVGLSDPEGQRHWQWVDQTPYN 146
Cdd:cd03588    1 CEEGWDKFQGHCYRHFPDRETWEDAERRCREQQGHLSSIVTPEEQEFVNNNAQDYQ--WIGLNDRTIEGDFRWSDGHPLQ 78

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|
gi 148536836 147 ESStfWHPREPSD---PNERCVVLNFRKSPKrwgWNDVNC 183
Cdd:cd03588   79 FEN--WRPNQPDNffaTGEDCVVMIWHEEGE---WNDVPC 113

C-type lectin-like domain (CTLD) of the type found in the type 1 transmembrane proteins: P(platlet)-, E(endothelial)-, and L(leukocyte)- selectins (sels); CLECT_selectins_like: C-type lectin-like domain (CTLD) of the type found in the type 1 transmembrane proteins: P(platlet)-, E(endothelial)-, and L(leukocyte)- selectins (sels). CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. P- E- and L-sels are cell adhesion receptors that mediate the initial attachment, tethering, and rolling of lymphocytes on inflamed vascular walls enabling subsequent lymphocyte adhesion and transmigration. L- sel is expressed constitutively on most leukocytes. P-sel is stored in the Weibel-Palade bodies of endothelial cells and in the alpha granules of platlets. E- sels are present on endothelial cells. Following platelet and/or endothelial cell activation P- sel is rapidly translocated to the cell surface and E-sel expression is induced. The initial step in leukocyte migration involves interactions of selectins with fucosylated, sialylated, and sulfated carbohydrate moieties on target ligands displayed on glycoprotein scaffolds on endothelial cells and leucocytes. A major ligand of P- E- and L-sels is PSGL-1 (P-sel glycoprotein ligand). Interactions of E- and P- sels with tumor cells may promote extravasation of cancer cells. Regulation of L-sel and P-sel function includes proteolytic shedding of the most extracellular portion (containing the CTLD) from the cell surface. Increased levels of the soluble form of P-sel in the plasma have been found in a number of diseases including coronary disease and diabetes. E- and P- sel also play roles in the development of synovial inflammation in inflammatory arthritis. Platelet P-sel, but not endothelial P-sel, plays a role in the inflammatory response and neointimal formation after arterial injury. Selectins may also function as signal-transducing receptors.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148536836  79 YFISTESASWQDSEKDCARMEAHLLVINTQEEQDFIFQNLQEESA--YFVGLSDPEGQrhWQWVDQTPYNESSTFWHPRE 156
Cdd:cd03592    3 YHYSTEKMTFNEAVKYCKSRGTDLVAIQNAEENALLNGFALKYNLgyYWIDGNDINNE--GTWVDTDKKELEYKNWAPGE 80

                         90       100       110
                 ....*....|....*....|....*....|....*..
gi 148536836 157 PSDP-NERCVVLNFRKSPKrwgWNDVNCLGPQRSVCE 192
Cdd:cd03592   81 PNNGrNENCLEIYIKDNGK---WNDEPCSKKKSAICY 114

C-type lectin-like domain (CTLD) of the type found in lectins TC14, TC14-2, TC14-3, and TC14-4 from the budding tunicate Polyandrocarpa misakiensis and PfG6 from the Acorn worm; CLECT_TC14_like: C-type lectin-like domain (CTLD) of the type found in lectins TC14, TC14-2, TC14-3, and TC14-4 from the budding tunicate Polyandrocarpa misakiensis and PfG6 from the Acorn worm. CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. TC14 is homodimeric. The CTLD of TC14 binds D-galactose and D-fucose. TC14 is expressed constitutively by multipotent epithelial and mesenchymal cells and plays in role during budding, in inducing the aggregation of undifferentiated mesenchymal cells to give rise to epithelial forming tissue. TC14-2 and TC14-3 shows calcium-dependent galactose binding activity. TC14-3 is a cytostatic factor which blocks cell growth and dedifferentiation of the atrial epithelium during asexual reproduction. It may also act as a differentiation inducing factor. Galactose inhibits the cytostatic activity of TC14-3. The gene for Acorn worm PfG6 is gill-specific; PfG6 may be a secreted protein.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 148536836 124 YFVGLSD-PEGQRHWQWVDQTPYNESSTFWHPREPSDPNER--CVVLNFRKSPkrwgWNDVNCLGPQRSVCE 192
Cdd:cd03601   51 YWVGADNlQDGEYDFLWNDGVSLPTDSDLWAPNEPSNPQSRqlCVQLWSKYNL----LDDEYCGRAKRVICE 118

C-type lectin-like domain (CTLD) of the type found in human collectins including lung surfactant proteins A and D, mannose- or mannan binding lectin (MBL), and CL-L1 (collectin liver 1); CLECT_collectin_like: C-type lectin-like domain (CTLD) of the type found in human collectins including lung surfactant proteins A and D, mannose- or mannan binding lectin (MBL), and CL-L1 (collectin liver 1). CTLD refers to a domain homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. The CTLDs of these collectins bind carbohydrates on surfaces (e.g. pathogens, allergens, necrotic, or apoptotic cells) and mediate functions associated with killing and phagocytosis. MBPs recognize high mannose oligosaccharides in a calcium dependent manner, bind to a broad range of pathogens, and trigger cell killing by activating the complement pathway. MBP also acts directly as an opsonin. SP-A and SP-D in addition to functioning as host defense components, are components of pulmonary surfactant which play a role in surfactant homeostasis. Pulmonary surfactant is a phospholipid-protein complex which reduces the surface tension within the lungs. SP-A binds the major surfactant lipid: dipalmitoylphosphatidylcholine (DPPC). SP-D binds two minor components of surfactant that contain sugar moieties: glucosylceramide and phosphatidylinositol (PI). MBP and SP-A, -D monomers are homotrimers with an N-terminal collagen region and three CTLDs. Multiple homotrimeric units associate to form supramolecular complexes. MBL deficiency results in an increased susceptibility to a large number of different infections and to inflammatory disease, such as rheumatoid arthritis.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148536836  79 YFISTESASWQDSEKDCARMEAHLLVINTQEE----QDFIFQNLqeeSAYFVGLSDPEGQRHWQWVDQTPYNESStfWHP 154
Cdd:cd03591    4 FVTNGEEKNFDDAQKLCSEAGGTLAMPRNAAEnaaiASYVKKGN---TYAFIGITDLETEGQFVYLDGGPLTYTN--WKP 78

                         90       100       110       120
                 ....*....|....*....|....*....|....*....|
gi 148536836 155 REPSDPN--ERCVVLNfrkspKRWGWNDVNCLGPQRSVCE 192
Cdd:cd03591   79 GEPNNAGggEDCVEMY-----TSGKWNDVACNLTRLFVCE 113

C-type lectin protein; Provisional

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*...
gi 148536836  67 CPKNWKSFSSNCYFISTESASWQDSEKDCARMEAHLLVINTQEEQDFI 114
Cdd:PHA02867  49 CPDEWIGYNSKCYYFTINETNWNDSKKLCDVMDSSLIRFDNIETLNFV 96

C-type lectin (CTL)/C-type lectin-like (CTLD) domain subgroup 1; a subgroup of protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins; CLECT_1: C-type lectin (CTL)/C-type lectin-like (CTLD) domain subgroup 1; a subgroup of protein domains homologous to the carbohydrate-recognition domains (CRDs) of the C-type lectins. Many CTLDs are calcium-dependent carbohydrate binding modules; other CTLDs bind protein ligands, lipids, and inorganic surfaces including CaCO3 and ice. Animal C-type lectins are involved in such functions as extracellular matrix organization, endocytosis, complement activation, pathogen recognition, and cell-cell interactions. CTLDs may bind a variety of carbohydrate ligands including mannose, N-acetylglucosamine, galactose, N-acetylgalactosamine, and fucose. CTLDs associate with each other through several different surfaces to form dimers, trimers, or tetramers from which ligand-binding sites project in different orientations. In some CTLDs a loop extends to the adjoining domain to form a loop-swapped dimer.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 148536836  79 YFISTESASWQDSEKDCARMEAHLLVINTQEEQDFIFQNL-QEESAYFVGLSDpeGQRHWQWVDQTPynESSTFWHPrEP 157
Cdd:cd03602    3 FYLVNESKTWSEAQQYCRENYTDLATVQNQEDNALLSNLSrVSNSAAWIGLYR--DVDSWRWSDGSE--SSFRNWNT-FQ 77

                         90       100       110
                 ....*....|....*....|....*....|....
gi 148536836 158 SDPNERCVVLNFRKSpkrwgWNDVNCLGPQRSVC 191
Cdd:cd03602   78 PFGQGDCATMYSSGR-----WYAALCSALKPFIC 106